1. Field of the Invention
The present invention relates to a compressor preferably applied to automotive air conditioning, and more particularly, to a multi-cylinder reciprocating compressor including single-head-type pistons.
2. Description of the Related Art
Hitherto, reciprocating compressors are used for a refrigerating circuit and the like of automotive air conditioners. A conventional reciprocating compressor includes a cylinder block having a plurality of cylinder bores in which pistons are accommodated and a front housing disposed at an end of a casing. A cylinder head is disposed at the other end of the cylinder block of the casing through a valve plate unit. Further, the compressor includes a rotating shaft inserted into the cylinder block of the casing passing through the front housing, a rotor disposed sequentially from a side near to the front housing of the rotating shaft, a swash plate, and a swing plate. An end of the rotor is rotatably supported by the inner wall of the front housing and the other end thereof is coupled with an end of the swash plate disposed around the rotating shaft through a hinge mechanism. The swing plate is disposed around the cylindrical portion of the swash plate at the center thereof. The swing plate is swingable in an axial direction with respect to the swash plate but the rotation thereof around an axis is prevented. The pistons accommodated in the cylinder bores are connected to the other end of the swing plate in a vicinity of the periphery thereof through piston rods.
Further, the cylinder head includes a first cylinder head unit and disposed outside of the compressor and a second cylinder head interposed between the first cylinder head unit and the valve plate unit. These first and second cylinder head units are fixed by bolts.
The first cylinder head unit includes a bottom wall, a side wall disposed around the bottom wall and a partition disposed inside of the side wall. A refrigerant introducing through hole is formed through the bottom wall at the center thereof. The interior of the first cylinder head unit is widened and forms a suction chamber between it and the outside bottom surface of the second cylinder head unit. Further, a discharge port is formed at a position outwardly of the center of the bottom wall and the periphery of the discharge port is arranged as a boss section formed integrally with the partition. Further, a discharge chamber is formed between the side wall and the valve plate unit.
In the conventional reciprocating compressor, when the rotating shaft is rotated by an external drive source, the rotor is rotated by the rotating shaft and the swash plate coupled with the rotor is rotated thereby. The rotation of the swash plate is converted into the axial reciprocating motions of the pistons in the cylinder bores through the swing motion of the swing plate and through the reciprocating motions of the piston rods.
With this arrangement, refrigerant from an external refrigerant circuit is introduced into a suction room from the refrigerant introduction port through a suction chamber and reaches the cylinder bores from the suction room through suction ports. The refrigerant in the cylinder bores are compressed by the pistons and discharged into the discharge chamber from a discharge outlet. The compressed refrigerant discharged into the discharge chamber is supplied to the external refrigerant circuit through a discharge port.
As described above, the conventional cylinder head has a series of partition for separating the inner space thereof into the suction room and the discharge chamber, and the suction room is arranged as a common suction space with no partition. Therefore, refrigerant gas introduced from the introduction port of the cylinder head is sequentially sucked into the respective bores from the suction port of a valve plate coupled with the cylinder block according to the suction stroke of the pistons.
In the conventional suction gas paths, each of the paths from the refrigerant introduction port of the cylinder head to each of the suction ports of the respective bores has a different length, even if it is disposed on the center axis of the cylinder head, depending on various factors such as the position of the discharge port and the interference by reinforcing members. Moreover, the refrigerant gas is sucked in the common suction space, causing pressure pulsation in the suction gas by the mutual interference of the gas sucked into the respective bores.
The pressure pulsation is transmitted to an evaporator in a compartment through piping, from which a problem arises in that unpleasant noise is generated by resonance.
It is an object of the present invention to provide a cylinder head assembly capable of preventing noise in a compartment by preventing mutual interference of suction gas and by avoiding suction pulsation caused by pressure change.
It is another object of the present invention to provide a reciprocating compressor including the above cylinder head assembly.
It is still another object of the present invention to provide a cylinder head assembly which can be assembled simply.
It is yet another object of the present invention to provide a reciprocating compressor including the above cylinder head assembly.
According to an aspect of the present invention, there is provided a reciprocating compressor which includes a cylinder block having a plurality of bores disposed in parallel with each other, a valve plate having suction ports corresponding to the respective bores, a cylinder head for closing the outer end of the cylinder block through the valve plate which is held between the cylinder head and the cylinder block and on which suction valves and discharge valves are mounted, and pistons inserted into the respective bores so as to reciprocate in a predetermined phase difference, said cylinder head having a suction chamber formed in the cylinder head adjacent to a refrigerant introduction port, and partitions disposed in the cylinder head around the outer periphery of the suction chamber for introducing suction gas into the respective bores.
According to another aspect of the present invention, there is provided a cylinder head assembly which is disposed at an end of a cylinder block having a plurality of cylinder bores of a compressor for closing the outer end of the cylinder block, and Which includes a cylinder head main body acting as an outer shell, and a partition plate for constituting a discharge chamber. In the aspect of the present invnetion, the cylinder head main body comprises a refrigerant introduction port, a suction chamber disposed adjacent to the refrigerant introduction port, and partitions disposed in the cylinder head around the outer periphery of the discharge chamber for introducing suction gas into the respective bores.